If a light gluino exists, the lightest gluino-containing baryon, S0, is a possible candidate for self-interacting dark matter. In this scenario, the simplest explanation for the observed ratio ΩDM/Ωb ≈ 6 - 10 is that mS0 ≃ 900 MeV c-2; at present, this is not excluded by particle physics. Such an S0 could be present in neutron stars, with the hyperon formation serving as an intermediate stage. We calculate equilibrium compositions and the equation of state for high-density matter with S0, and we find that for a wide range of parameters, the properties of neutron stars with S0 are consistent with observations. In particular, the maximum mass of a nonrotating star is 1.7 - 1.8 M⊙, and the presence of S0 is helpful in reconciling observed cooling rates with hyperon formation.
Bibliographical noteFunding Information:
The research of G. R. F. is supported in part by NSF grant PHY 99-96173. The idea that S0 could be a DM candidate and the constraints on such a scenario were developed by G. R. F. in collaboration with D. Spergel and P. Steinhardt. That work will be reported in greater depth elsewhere (G. R. Farrar, D. N. Spergel, & P. J. Steinhardt 2001, in preparation), but a brief description can be found in Wandelt et al. (2000). S. B. and T. P. thank NYU for the hospitality that facilitated this research.
- Dark matter
- Dense matter
- Elementary particles
- Equation of state
- Stars: neutron